


Density of the Human Heart

by StHoltzmann



Series: New Toys [4]
Category: Ghostbusters (2016)
Genre: Angst and Feels, BDSM References, Denial of Feelings, Dubious Science, F/F, Footnotes are sexy, For Science!, I Wrote This Instead of Sleeping, I am totally not channeling my feelings about Holtzmann into this, Insomnia, LGBTQ Female Character, Light Smut, POV Second Person, Physics, Reader-Insert, Unresolved Emotional Tension, emotional maelstrom, stupid Archimedes jokes
Language: English
Status: Completed
Published: 2016-09-04
Updated: 2016-09-04
Packaged: 2018-08-13 01:05:51
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,230
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7956127
Author URL: https://archiveofourown.org/users/StHoltzmann/pseuds/StHoltzmann
Summary: <blockquote class="userstuff">
              <p>Sexy funtimes on the outside, emotional trash fire on the inside. Also, science.</p>
            </blockquote>





	Density of the Human Heart

**Author's Note:**

> This story is a little different from the others: most of the toy-testing is just summarized or alluded to, and the main testing scene is brief. At the same time, the emotional side of the story is picking up.
> 
> (I totally reserve the right to go back later and write some more stories that flesh out--cough cough--the scenes that are only referenced here!)

You manage to meet up with Holtzmann several times in the next couple of weeks. For research, of course. Your labmate observes that you have a "pep in your step" and asks if you've got a new boyfriend. You give him a very satisfying lecture about not making assumptions.

There’s a lot you’re _not_ saying these days, either to Holtzmann or to yourself. (And never mind your colleagues.) So yes, you’re happier and healthier in some respects, but you’re also constantly pushing away the feeling that you’re hurtling towards a cliff. You’re working extra hard to make your schedule flexible, _and_ you’re sublimating your actual wishes into productivity. You’re eating breakfast, lunch, and dinner (when you remember to eat) at your desk. The end result is that you’re getting plenty of your own research done, and pushing yourself to take risks that might pay off. Sometimes you dream of publishing a paper that’s so revolutionary, even Holtzmann would notice.

Among other things, Holtzmann has followed up on her note to stop neglecting your mouth and lips. There's a gag that inflates inside your mouth in a way that's simultaneously discomfiting and arousing, a slightly electrified tongue clip that attaches to a pair of nipple clamps via a wired chain, and a posture collar that comes up far enough to cover, and then pulsate along, your lips. They all get pretty high marks from you. Holtzmann, though, is frustrated. She can't find an adequate substitute for plain old kissing, let alone a technologically improved version of it. You have a low-tech solution to this problem, but—of course—you bite it back.

There are other toys, too: the haptic cycling shorts that give you a delightful phantom spanking, the robotic fisting arm (you needed a day to recover from that one, but it was worth it), the very alarming-looking sensory deprivation pod that manages to fill every orifice except your nose, and which leaves you feeling both immensely satisfied and slightly detached from reality…

After the testing sessions, Holtzmann’s been intermittently quizzing you just as she promised. Because she doesn’t seem to register anything unusual about your knowledge, the quizzes are the one time where you throw caution to the wind. You always give your best guesses, drawing both on years of youthful tinkering and the attention that you pay to academic disciplines adjacent to yours. Holtzmann is pleased whether you’re correct or miss the mark (or are wildly off-base). She’s delighted when you’ve caught on to a feature or design element, and she smirks proudly when you’re baffled. Now that you think of it, maybe her wholehearted passion for research and invention is rubbing off on you a little bit. Some of your post-doc cynicism has been cleaned away.

Sometimes, in fact, you get an idea for a software improvement to her hardware. When that happens, however useful you think it might be, you have to bottle yourself up again.

Holtzmann divides her time between the control booth in the room with you now. You like this much more than when she was out of sight. At the same time, it’s more frustrating, because she's _right there_ and yet completely out of reach. (And also because you just can’t tell what she’s thinking when she watches you.)

There are a couple of days when you have to take the paperwork home because there’s a call from Ghostbusters HQ, but you don’t mind. When a call comes in, you briefly get to see another side of Holtzmann: the bad-ass (though still not necessarily serious), heroic side. Naturally, this is _beyond_ hot—maybe even more so than the intriguingly weird equations and hypotheses that she scribbles on the whiteboards and notebooks in the warehouse.

You keep noticing things she does and says and wears. There’s the many different positions you catch her in when you come downstairs: never just sitting on a chair, always draped over something, propped up on something, spinning around on something, perched atop something. There’s the way her glorious, sexy brain doesn’t just do lateral thinking, but multi-dimensional thinking. There’s the way that you never know what’s going to come out of her mouth next, and how you’re always utterly disarmed by whatever she says (even when you’re not sure what it means, or whether she’s at all serious). There’s the continued alchemy of her clothing, which—if each piece were an ingredient—would be like if she stirred together anchovies, marmalade, brandy, custard, Vegemite, and hot dogs, but then produced an amazing chocolate cake.

Also her lips.

And the damn dimple.

All of this would be overwhelming and exhausting on almost anybody else, but it’s Holtzmann. Anyone else would be faking it, putting on weirdness as an affectation. But Holtzmann is always Holtzmann. You remember her saying "I wouldn’t inflict myself on anyone else" and shake your head. How can she believe that anyone would think she was an infliction?

There's a day when she opens the door and music is playing. She dances back into the warehouse and, for a while, you join her, even though dancing to “Exquisite Dead Guy” is nearly impossible. You hope she didn’t see you almost trip over a mess of magnets and lasers when you heard John Linnell sing “How'm I supposed to let you know/the way I feel/about you?” It's dorky magic and you cling to the memory because you know it should never happen again.

Probably.

So many conflicting thoughts. You can’t tell her that your tiny, harmless crush on her has gotten completely out of hand. You can’t tell her you’re a scientist yourself. You can’t tell her that she might have come to a lecture you gave once. Any of those things, let alone all of them together, would disqualify you as her research subject. And she would definitely be upset that you’ve been contaminating her data all this time. And then you would never see her again.

And yet you almost want her to guess. It would be a disaster, but at least it would be a resolution.

When you’re in bed, these thoughts spiral endlessly through your head. You can’t deal with them, but you also can’t sleep. So you solve the problem efficiently: you start sleeping less. It’s starting to show in your face, but it’s letting you get even more work done. And the lab is pretty quiet at 3 AM. So this is fine.

Isn’t it?

* * *

Right now it’s midnight at the lab, and while a lot of your colleagues are probably still working, almost all of them are doing it at home. It’s easier for you to focus on your work and not your own thoughts here, though. And it’s easier for you to work on envelope-pushing new ideas when other people aren’t wanting to use the same equipment.

You’re in the middle of looking over some promising new data when you get a text. It’s Holtzmann.

_You up?_

_Still at work tbh,_ you reply.

_Do you have to be?_

_…I do not have to be_. You make sure that your work is saved and backed up, and then you’re stuffing things in your bag and making for the door.

_Just finished A Thing. Could use some feedback._

Before you can reply, she adds: _Technically it’s not “””finished””” finished. But it will be._

 _ETA: ASAP,_ you text back, halfway out of the building.

* * *

Holtzmann meets you at the door. You wonder if she even needs to sleep, or if she just draws energy from kicking scientific and ghostly ass. Maybe that’s why she doesn’t have much food around.

“Hello, please put on this extremely attractive hat,” she says, holding out a weird-looking helmet. It’s beyond you to guess what it does, but it’s large and encumbered with a bewildering array of wires and lights.

“Um.” You put your bag down and take it. “Do I need to, you know…?” You gesture at your clothed body.

“Not tonight,” Holtzmann says. “Make with the haberdashery!”

You put it on your head gingerly and fasten the chin strap. Holtzmann reaches up to attach a couple of electrodes to the back of your neck. Then she flips a switch on the helmet

“It’ll feel like you’ve got bees. In your skull,” she says. This would have been useful information to have had ten seconds ago, when the buzzing started.

“Roger, bees. We’ve got bees.” Your head is buzzing unpleasantly.

“Hold tight, my child,” Holtzmann says serenely. “It’ll go away.”

Sure enough, the buzzing fades away to an undetectable level. As you give a sigh of relief, Holtzmann is pulling gloves onto your hands. They’re not like the half-finger driving gloves that Holtzmann wears. They’re made of something thin and stretchy, but there are flat wires running in them from the pads of your fingers into your palm. Holtzmann makes sure they’re on to her satisfaction, and then she steps back. (And lets go of your hands, which is a regrettable move as far as you’re concerned.)

“Now what?” you ask, a little nervous. This is very different from anything else you’ve done.

A wicked smile tugs at Holtzmann’s lips. She shrugs theatrically. “Who knows! Wander around, check out some of my stuff.”

Perplexing. But sure. You stroll over to a workbench and reach for something that looks like a catalytic converter, though you’ve never seen one with LEDs on it before.

“Not _THAT!_ ” Holtzmann yells, leaping between you and the workbench. Your hand winds up mashing into Holtzmann’s chest, and you take a sudden step backwards. As soon as your fingers touched her denim coveralls, you felt a sudden, firm stroke down your inner thigh. It makes your knees weak.

“Huh,” you say. You look around for something innocuous to pick up. There’s a vintage Rapidograph technical pen on the drafting table. You make eye contact with Holtzmann and reach for it. She doesn’t freak out, so you touch it with the index finger of your right hand. You feel your right breast being gently squeezed so realistically that you look down to be sure nothing is happening to your chest. And nothing is. You put your left index finger on the pen, and now they’re both feeling pleasantly squeezed. Lifting your fingers up gently and putting them back on the pen results in a rhythmic squeeze, and putting as many of your fingers on the pen as you can fit results in a harder, firmer grab.

“Innnteresting,” you say. You walk around a little more, touching the folding chairs, an Atari mug, an empty Chinese takeout container, a plastic crate, three different pairs of goggles, a sponge shaped like a strawberry, a balsa wood model, a lead weight, wedges of foam, a glow-in-the-dark marble, an Icelandic dictionary, the floor… (And you take the hint and do _not_ touch the large thermos, the naval gyrocompass, or the 1980s alarm clock.) You’ve now experienced a range of touches in different erogenous zones—more precisely, exactly the kinds of touches you like in exactly your favorite places to be touched. Your breasts, thighs, neck, mouth, and crotch are all feeling _very_ good, and you are aroused but confused.

“Is this a puzzle?” you ask. “It’s fun, but I’m not sure this is going to, you know, get me all the way there.”

Holtzmann considers. “I was picturing the final version as a slimmed-down kit that you—uh, somebody could just ramble around in. A real boredom-killer at bad parties or stupid meetings—as if there’s any other kind. But not necessarily a toy with a destination. Buuuut if you want to figure out the Rubik’s cube, be my guest!”

You look around for something else made of cloth like Holtzmann’s coveralls. Maybe the evoked sensations relate to the material being touched…You touch her lab coat, which is hanging on a hook, and you feel a gentle stroke of your inner thigh. That makes sense. Then you touch a soft paisley sock that’s laying on a shelf, and it feels like kisses on the back of your knees. Hmm.

“Please tell me this isn’t random? There’s a connection between what I’m touching and what I’m feeling, right?”

“That’s for me to know, and you to find out,” Holtzmann smirks. She leans back in a chair, props her feet up on the drafting table, and steeples her fingers.

“Gahhh.” You spend a few more minutes roaming around, gathering data. Well, stimulating yourself, and gathering data. You try to make some notes on a piece of paper to help you figure out the correlations, but pressing your fingers against the pencil results in such an intense tongue down your spine that you drop the pencil and have to give up. You’ll have to work it out in your head.

You move on, touching more things. Going back to a thing you’ve touched before does result in the same type of sensation. But things in similar use categories don’t, except for when they do. Shapes don’t seem to mean anything, nor colors. You’re touching more and more things and become more and more flushed and wobbly. On top of that, you’re distracted by your mental attempts to correlate the sensations and the materials, so it’s no surprise when you bump into some kind of cooling unit and have to catch yourself with a fast, desperate, two-handed grab at the stair railing. This results in such a sharp lashing of your clitoris that you have to sit down to recover.

Holtzmann is still watching you, tapping her fingertips together. Her hair is falling over her face, and her transparently fake ultra-serious expression is just as attractive as her brilliant smiles are.

You are both sexually and intellectually frustrated. “I’m not usually this dense,” you mutter to yourself.

Wait a minute.

Density. _Density_.

The sock looks like it’s made of bamboo yarn. That’s probably pretty low density for a solid, maybe around 1 g/cm³. But the coveralls are cotton, which is something like 50% more dense. You look around and spot a candle on a shelf next to a fire extinguisher. Beeswax is around the same density as bamboo. You touch the candle and: kisses! On the back of your knees! Then that should mean that the human body…Before you can talk yourself out of it, you walk over to Holtzmann and boldly reach a finger toward her face. She just grins, maddeningly, and you poke her right in the dimple. And there are the kisses again, as your increasingly wobbly knees can attest. "I don't understand how that's possible," you mutter. Measuring density is not something you should be able to do with just a glove.

Holtzmann's expression is positively Sphinx-like. "Let's just say I had a 'Eureka' moment."

Damn, she's good.

You move away from Holtzmann before you do something else rash, and look around for the metal-casting equipment that you know has to be around here somewhere. When you spot it in a back corner, you find bags of sand nearby. You poke a finger into one that’s open, and bingo: your inner thigh is being petted again.

_Thank you, materials science trivia!_

Holtzmann’s eyebrows raise. She scoots around in her seat, drapes her legs over a chair arm, leans her elbow on the drafting table, and props up her chin on her hand. “ _Go on_ …” she says, as though you’d been speaking aloud.

You smile and start bringing objects to a suspiciously clean and empty workbench. Holtzmann’s still watching, eyes bright.

You get your choice of objects assembled and look back at Holtzmann. She grins and leans forward, resting her foot on a wheeled stool. “Well?”

“The sensations are pegged to the density of the materials,” you say.

“Gold star.” Holtzmann kicks the stool over to you. “Bring it on home, baby.”

You do, though the stool is less than ideal since it means you also have to work on keeping yourself upright. It’s the strangest form of masturbation you’ve ever encountered. You’re fully clothed, and you have the usual number of limbs and range of movement, but now you can essentially stand outside of your body and do things to yourself that are physically impossible. You can cause your nape to be licked at the same time that your lips are being pressed, and any other combination you can manage. You can hold three things in one hand and two in the other and let all of the different feelings happen at once, as though you’re surrounded by an invisible cluster of women (you are definitely not picturing a ring of Holtzmanns around you).

It takes you a while to try out different combinations, until you have a plan for what you want. You have your spine thoroughly licked, your thighs caressed, your lips pressed, your nipples pinched, your most sensitive spots kissed, and finally, your clitoris (via a stainless steel spoon) stroked until you are about to fall over. You look like some kind of possessed DJ but you don’t care. The best part is that no part of your body, clit included, is getting tired of the stimulation, since nothing’s being physically touched. But there are still limits to your endurance.

(Also, your neck is getting tired. That is one clunky helmet.)

You finally sigh and put the spoon and the Erlenmeyer flask down. Your face is flushed and your hair is wild, and you’re going to have to change your underwear even though you never took off your pants. “That was very peculiar, but also very fun.”

Holtzmann offers you a hand up. “‘Peculiar fun’ is my middle name,” she says. “And yours must be ‘eternally full of surprises.’ I was totally not expecting such a methodical approach or excellent conclusion.” Holtzmann sounds as though she isn’t used to admitting surprise.

You are satisfied on multiple levels at the moment, though you can feel exhaustion creeping in. You put Holtzmann’s things back, not wanting to disrupt her chaotic brand of order, and then go wash your face and change your underwear in the bathroom.

Paperwork time. It's a little hard to concentrate on, but you rub your eyes and get through it while Holtzmann pokes at the helmet.

When you get up and pick up your bag to go, Holtzmann catches you by the elbow and turns you so that your face is in the light. “Not to go all Patty on you—Patty’s my co-worker, she’s the greatest—but kid, you look like you need a vacation. And all the sleep. And If _I’m_ saying that, it must be true.”

Embarrassed, you shrug away from her. “I’m OK. I’m doing work I enjoy. I’ll sleep later. _You_ know.”

Holtzmann nods, and you suddenly, guiltily, wonder if she’s losing sleep to this project herself.

“I know. However, I hear there are limits to the human body.” Holtzmann grins and rolls her eyes. Then she glances away from you and adds in an awkward rush, “So, just take care of yourself for me, OK?”

You sigh. “I will. I’m going home to get some sleep now.”

You go home through the drizzle and the darkness, and you do try. But if anything, Holtzmann’s expression of concern has only made your spiral of self-doubt and anxiety deepen. When the sun struggles to rise and break through the clouds, you’re still awake.

**Author's Note:**

> I hope that wasn't too jarring of a difference from the previous story! Coming up next is the final story in this emotional/sexual arc, but I may yet either continue it or fill it in. We'll see...
> 
> Thanks for the encouragement on my very first smutfic series! It's been very helpful.
> 
>  
> 
> \- ERRATA -
> 
> They Might Be Giants, "Exquisite Dead Guy": ["video" (sound only)](https://www.youtube.com/watch?v=TN1wHqkTAyo), [lyrics](http://genius.com/They-might-be-giants-exquisite-dead-guy-lyrics) (such as they are)
> 
>   [Haptics](http://haptics.seas.upenn.edu/)
> 
>  
> 
>  
> 
> \- ACKNOWLEDGMENTS -
> 
> Thanks to the delightfully evil mind of E., who came up with the idea of gloves that translate mundane contact into erotic sensations.


End file.
